This invention relates to the environmental control of squirrels and similar animals which cause damage to foliage and growing materials, particularly trees. The invention is specifically concerned with a unique type of physical barrier having the capability of preventing the passage of small climbing animals from reaching the upper portions of a tree.
Squirrels and similar animals which nest in trees, create a serious problem in various areas such as orchards, nurseries as well as domestic landscapes. These animals very often nest and feed on the leafs and fruit such as nuts growing in the upper reaches of the trees. The damage can be quite serious depending on the amount of infestation. From an economic standpoint alone, squirrels can rapidly strip a nut tree leaving nothing available for the grower to market. The use of chemical agents such as pesticides has not always been an effective solution. The pesticides must be continually applied, are quite expensive and very often cause more damage to the surrounding environment, not to mention the human population, than to the rodent at which it is directed.
Attempts have been made in the prior art at using physical barriers to prevent squirrels and similar animals from climbing into trees; however, these devices have been found to be only marginally effective at best.
Many of the prior art devices are cone shaped barriers having a central opening through which the tree trunk is positioned. The prior art U.S. Pat. No. of Brunson 104,418, Record No. 35,471 Parks No. 110,996 and Carder No. 2,999,479 all disclose tree guards based on this concept. Neither Parks No. 110,996 nor Record No. 35,471 are provided with adjustment means once the device is positioned around a tree trunk. Brunson No. 104,418 includes coil springs or ties to join the edges of the cone together. Carder No. 2,999,479 similarly employs two welded tongues for fastening the device around a tree. Because of the type of fastening means employed in both Carder and Brunson, the range of tree trunk sizes which the device will fit is limited. The straps provide only a small margin of adjustment. In addition, stretched coils and strap means extending along the outer margin of the guard provide the climbing animal with a secure footing and hold thereby allowing it to more easily pass the device.